The present invention relates to a valve assembly and in particular, although not limited to, a valve assembly for opening and closing the end of fluid passageways. The present invention further extends to a method of opening and closing a valve assembly.
It is a common requirement in many industries to be able to open and close the ends of fluid passageways. Fluid passageways require opening and closing in a variety of circumstances, for instance before/after the coupling/decoupling of two fluid passageways (e.g. pipes or hoses). It is particularly desirable to combine the opening and closing of the valves with coupling and decoupling of the two fluid passageways, such that when the fluid passageways are decoupled the valves are closed and when the fluid passageways are coupled the valves are opened.
WO 2006/005949 discloses various valve embodiments that open and close the fluid passageways, wherein the opening and closing of the valves is initiated by the coupling and decoupling respectively of a male and a female coupling member. A closing member operated by a spring closes the fluid passageways. In high pressure applications the spring is required to store a large amount of energy in order to urge the closing member closed against the pressure of the fluid. This occurs when the couplings are broken whilst pressurised fluid is contained within the coupling (e.g. during so called ‘hot break’ conditions). If the springs could not close the apertures against the pressurised fluid when the couplings are decoupled, decoupling could only occur in ‘dry’ conditions. Moreover, when one or both of the decoupled fluid passageways contain pressurised fluid (e.g. during so called ‘hot make’ conditions), the force required to couple the coupling members is dependent on the pressure of the fluid. In high pressure applications, this coupling force may be unachievable by spring loaded means thus known couplings can only be made when they are dry. Accordingly, in a wide number of applications, the coupling assembly is capable of dry coupling only.